I've picked up hundreds of gallons from barrels and dumpsters at restaurants (by permission) using a scoop made from a one-gallon motor-oil jug. I stack up two cubees and hold a transmission-oil funnel (long and skinny) in the top of the top cubee. I've cut off a few inches of the skinny end of the funnel. About eight scoops make a cubee full. I count the scoops and slow down toward the end. I keep the scoop and funnel in a 5-gallon plastic pail with a lid, and always have a rag or two handy. If the level in the barrel is low, I place a rag on the lip to keep my sleeve clean. Keeps it simple. Steve